Following Green's formal withdrawal, Alastair McCapra, returning officer for the CIPR election, closed the online vote on Friday and opened a 48-hour window for any complaints about the process of the election to be raised.
The CIPR is now organising an independent panel made up of non-CIPR members or PR professionals, to take an objective view of the evidence it has received. The body has received multiple complaints, but declined to say how many.
Martin Horrox, regulatory consultant at the CIPR, is in charge of organising the panel.
Current CIPR president Sarah Pinch said in a statement sent to members today: "The nature of the complaints and appeals now being heard are confidential and should remain as such until the panel is able to complete their investigations.
"Once the independent panel has concluded its work, the outcome of the election will be published. An outcome may include a result or a decision to re-run the ballot. As soon as we can, the board of Directors will ensure that members are informed of the outcome of the election."
In his blog, Green explained his reasons for pulling out: "My decision to stand was prompted by a desire to champion the cause of democracy within the institute and to avoid, for the third year running, the post of president being unopposed. Running for president has frankly been a mixed experience where I have since lost the appetite and desire to lead the organisation."
The new president will serve a three-year term on the CIPR Board of Directors as president-elect in 2016, president in 2017 and past president in 2018.
The election has provoked comment on Twitter.